Grating



Oct. 27, 1953 P. KERRIGAN, JR

GRATING 2 Sheets-Sheet 1 Filed Dec 6, 1950 INVENTOR. PHILLIP KERRIGAN,JR.

ATTORNEYS Oct. 27, 1953 P. KERRIGAN, JR

GRATING 2 Sheets-Sheet 2 Filed Dec. 6, 1950 mm ER WR E K m L L H D.

ATTORNEYS Patented Oct. 27, 1953 GRATING Philip Kerrigan, J r., Nashville, Tenn., assignor to Kerrigan Iron Works, Inc., Nashville, Tenn., a. corporation of Tennessee Application December 6, 1950, Serial No. 199,450

3 Claims.

The present invention relates to non-skid gratings of the type commonly employed for walkways on top of railroad freight cars, and for the flooring of fire escape structures on buildings, for the coverings over sidewalk openings, and for stair treads, and the like. The grating disclosed herein may also be employed as a floorwork foundation to be covered by concrete, asphalt, or other such materials, when used in building structures, such as parking buildings, and it can be similarly employed as such a foundation in the flooring of bridge and similar constructions which are designed to handle heavy traffic.

A principal object of the invention is to provide such a grating structure characterized by the simplicity and cheapness of the parts employed, and which may be rapidly and conveniently fabricated, and assembled into the structure where it is to be used.

When employed as a grating uncovered by concrete, asphalt, or the like, the invention has pronounced advantages, in its provision of a surface which will minimize the possibility of a person's slipping and falling, when walking over the surface. These advantages are of particular importance when the grating is used, for example, as a walkway on top of freight cars, and when used as a flooring in industrial plants, in hazardous or confined locations, or in locations where persons may be required to carry heavy objects over the grating.

The construction provided also resists the collection of ice and snow on the grating, and is designed so that any ice and snow which does collect, may be readily removed. The grating is also of such nature as to provide an adequate walking surface, yet permitting the passage of a maximum amount of light through the grating.

It will also be observed that the parts of the structure are assembled to one another in such manner that a very strong grating assembly is provided and the arrangement of the assembled parts of the grating is such as to adequately resist longitudinal and transverse stresses, and to evenly distribute the weight of heavy loads throughout the grating structure. The advantages just mentioned are also applicable when the grating is used as a reinforcement for concrete or asphalt floorings, as previously mentioned.

Referring to the drawings, which disclose cer tain preferred assemblies of the invention:

Fig. 1 is a top plan view of a grating assembly.

Fig. 2 is a transverse sectional view of the grating, taken along the line 2-2 of Fig. 1.

Fig. 3 is a perspective view of a portion of one of the grating units.

Fig. 4 is a detail view, showing the manner in which one of the cross-bars is welded by elec- 2 triclty and pressure, into the upper edge of one of the longitudinal plates.

Fig. 5 is a similar perspective view of a. section of a grating unit, showing the optional incorporation therein of bottom strengthening transverse bars.

Fig. 6 is a transverse vertical sectional view taken along the line 6-43 of Fig. 5.

Fig. '7 is a similar perspective view of a portion of one of the grating units, showing the use of both top and bottom transverse bars, and

Fig. 8 is a transverse vertical sectional view taken along the line 88 of Fig. '7.

Referring to Fig. 3, the grating comprises a plurality of spaced parallel, longitudinally extending flat metal plates Pl, P2, P3, P4, having upper edges which lie in substantially the same horizontal plane and form a walking surface, the upper edges of said plates comprising alternating peak portions K and recessed portions R, with peak portions of one plate disposed in transverse staggered relationship with respect to those of adjacent plates and in transverse alignment with the recessed portions of said adjacent plates. The grating further comprises a plurality of spaced straight parallel bars BI, B2, B3 and B4 secured to the plates in transverse relationship with respect thereto and across the upper edges thereof, the bars passing through the recessed portions R of the upper edges of the plates. It will be noted that the portions R are of substantially greater width than the widths of the peak portions K, and that the widths of the recessed portions are substantially greater than the diameters of the bars BI, B2, B3 and B4, whereby the bars may extend between the staggered peak portions of the adjacent plates.

The recessed portions R each have a relative- .ly long base surface [0, which merges at its opposite ends into upwardly sloping (preferably concave) end surfaces I2, the latter forming the side walls of the peak portions K. The depth of the recessed portions is such that when the bars are pressure welded downwardly against the surfaces 12, the top side of the bars will be positioned substantially in the top plane of the peak portions K, thereby providing a substantially smooth walking surface, without requiring excessive downward penetration of the bars into the plates, in the accomplishment of an effective union between the bars and plates, by the pressure-electric welding operation, which is well known in the art.

It will be understood that the bars Bl-B4 may have various configurations in cross-section, such as circular, triangular, square, or of other polygonal shape, but it is preferred that these bars should have exterior surfaces of roughened or knurled nature, in order to provide maximum anti-skid capabilities. I have 3 found that bars which are formed in helical or twisted shape, as disclosed, function unusually well in the assembly of "the invention, both with respect to the convenience and effectiveness of the welding operation, and in the anti-skid performance of the resulting structure, such bars cooperating with the staggered arrangementof g-lti'ldihal plates, andthe transverse bars will more widely spaced from; one another; than use longitudinalplates. In Fig. 3, a useful grating unit might have the bars spaced as: between Bi and- TBI, the bars B2 and B3 being shown in Fig. 3 to illustrate the flexibility of the application of the invention, as applied to a particular installation. in additional transverse bars? may be provided as required. In Fig. 3, the bars Bi and 'B3' are shown positioned closely adjacent" to one another, itbeing noted thatbars-BZ 133T pass on opposite sides of and in contact with the peak H on the plate P3, and that these same 'b'ars" pass through a common recessed portion F6, but at opposite ends thereoi ijnthe plate'P l'. It will be understood that" additional cross bar'smay be employed in a 'particular' design, up to" a point where all reces's'ed portions of theplates' will receivetwo of the cross bars", or stated otherwise, up to a pomtwhere' each of the peaks in" the plates will have" a cross bar mounted on opposite sides thereof and in welding" contact therewith. How-- ever, in usual installations, it may only be neces'sar'y' to provide cross bars spaced-mm one another along the lengths of the plate, at a dista-ric'e equalto that between the bars BI and B4.

In the manufacture of the grating, relatively k long lengths of the plateare fabricated with uniformly arranged peak and recessed portions. These lengths are then cut in a manner as is illustrated in Fig. 3, so that the plates may be disposed in parallel relationship as in Fig. 3, with the peak portion of one plate lateral alignment with the center of the recessed portion" of an adjacent plate. When so assembled, the cross bars may be laid "into the recesses in' the manner' shown in Fig. 3, wherein a cross bar such as Bl will contact on one side of the bar, the side wall of one of the'peak portions of a plate; such as P4, and the bar will contact another of the peak portions of an adjacent bar, as F3, on its opposite side, this arrangementof contacting relationship with the staggered peak portions a1- ternating throughout the length of the bar, as it is laid in place across the top edges of the plates. When the bars are thus assembled, the effect will be to properly align the adjacent plates, or to maintain the said plates in proper augment;

Thereafter, and when a proper number of the bars have been so positioned, a heavy pressure plate is moved downwardly over the entire area of the grating unit, to exert downward pressure on the bars. At the same time, a welding current is passed between the contacting parts, in the manner well known inthe art, so that as the bars are pressed downwardly, the resistance at In eneral, the

4 the points of contact causes the metal to soften, melt or fuse, thus accomplishing a pressure welding union between thebars": and the plates at each of the points of contact;

Due to the position of the bars against the sloping sides li2 of the peak portions K, the welding union will be mainly against the sloping surfaces l2, and excessive penetration of the bars into* the bottom surfaces of the recessed portions; will not be necessary.

When the bars are assembled preparatory to the application or pressure and the electric current for welding, as shown in Fig. 3, a particular bar will be in contact on one side with a surface 12 of the peak portion of one plate, and it will be in similar contact with the sloping-surface of the peak portion of the next adjacent plate, onthe opposite side of the bar. There fore, when the downwardpressure isapplied, the bar will be forced both downward-1y andinwardly against each sloping surface l2 to: effect an intimate weld, and at the same time, any slight misalignment of the bar will' 'be automati cally corrected, for if 'a bar is not in proper-con tact with the sloping surface of the peak portion of a particular plate, the sloping surfaces of the oppositely facing peak portions of the adjacent' plates will tend to shift the slightly toward the sloping surface of the peak portion first mentioned, in order to' insure a; proper welding contact. m

In general, the result of the welding? operation will be, as shown Fig-4, to press the'bar down Wardly and inwardly against the slopingsurface f2 of eachpeak portion and a satisfactory union will bema'd'e without the necessityof completely burying the bar downwardly into the upper edges of the plates. A t-the same tixne,..as will also be apparent from Fig} 3', the-helical bar will be exposed on its inner side throughout a length equal to the distance between, for instance, platesPZ andPfl, it being noted that at the 2 6 the bar B4 is substantially completelyexposed, sothat this portion at the ha r" is open: for engagement by the edge of the sole of asnoe, wnereby a person could firmly brace himself against slipping, or when performing work whil'e standing on the grating, wl-iic'h would require some firm foot support against lateral slipping.

It will-be understood that the invention flexible enough to numerous variations in the arrangement of the bars across the plate. As stated, one useful construction would simply provide bar's spaced to about the distance between B1 and B4; Another variation would be to pro"- vide spaced pairs of such bars, the bars of a pair being substantially contiguous to one another, this being indicated by the arrangement of the bars B2 and B3. In other units, the whole top surface of the grating could be filled bars, closely spaced as are the bars B2 and B3.

In addition to the non sli-pping feature provided by the bars B I B4, the peak portions themselves are active'to provide a firm walking surface, the staggered arrangement of the peak portions providing an even surface on which to walk, the dimensions of the parts being such that a persons foot will be in contact with a number of the adjacent peak portions rather than passing downwardly between them. On the other hand, the plates are far enough apart so that the sole of the foot can be placed against the side faces of the plates near the upper ends thereoflor against the side faces of the peak portions when it is necessary to exert force in one direction when performing work on the platform, and a brace is afforded for the application of force in a direction at right angles to that just mentioned, by the bars BI-B4, with their relatively exposed portions, as previously mentioned.

In Fig. 5, a grating is disclosed having the same arrangement of peak portions K and recessed portions R, but the top bars Bl-B4 are omitted. In this design, the plates are held together by bottom bars 22 and 24, which also may be of the helical type, these bottom bars being pressed upwardly into the bottom edges of the plates while electric current is applied, to pressure weld the bars into the lower edges of the plates. In Fig. 7, a modification is shown wherein both bottom bars 22 and 24, and top bars Bi and B4 are provided, the bottom bars being located directly below the top bars.

In Figs. 1 and 2, an assembled grating is shown attached to the surface S, such as the top of a freight car.

Small connecting plates 20 are welded between certain of the longitudinal plates. at the lower edges thereof, and by means of suitable bolts 28, the entire grating structure is bolted to the top of the supporting surface.

While the top surface of the bars will be, in general, in substantially the same plane as the surfaces of the top of the peak portions, due to the helical design of the bars, at a particular union the peak portions may extend slightly above the upper surfaces of the bars.

While other forms of bars may be employed, 1 find the helical design of pronounced usefulness in the assembly of this invention, for this configuration of cross bar is best suited to be united by pressure-welding to the sloping sides of the peak portions. In prior art devices, the helical bars have been used only in association, so far as I am aware, in planes having only top edges, or top edges with substantially semi-circular grooves therein to receive the cross bars.

It will be understood that the terms 1ongitudinal and transverse are used herein in the relative sense, and are not intended as words of limitation.

By welding the bars into the slopes of the peak portions, intimate contact is made, yet greater advantage is taken of the helical anti-slip surfaces of the bars, particularly at and adjacent to the union. It has been found that the design disclosed herein has facilitated the welding operation, in that the cross bars are not required to completely penetrate into the upper edges of the plates.

I claim:

1. A grating comprising a plurality of similar load bearing spaced parallel longitudinally extending fiat metal plates, the upper edges of said plates comprising alternating peaks and recesses, said peaks being identical in configuration, and said recesses being identical in configuration and of substantially constant depth, said peaks of one plate being disposed in longitudinally aligned relationship with respect to one another and in transverse staggered relationship with respect to those of adjacent plates and in transverse alignment with the center of said recesses of said adjacent plates, and a plurality of load bearing spaced straight parallel bars integrally secured in transverse relation across the upper edges of said plates, said bars resting in the recesses of said plates and being secured to corresponding edges of said peaks of alternate plates, and being secured to the adjacent edge of the peak of the plate intermediate said alternate plates, the uppermost surfaces of said peaks and the uppermost surfaces of said bars being disposed in substantially the same plane forming a load supporting surface.

2. The grating set forth in claim 1, said peaks having edge surfaces which slope upwardly from said recesses, wherein said bars are integrally secured to said plates at the juncture of said peak sloping edge surfaces and said recesses.

3. The grating set forth in claim 1, and the bottom edges of said plates having transverse parallel bars pressure welded thereto, whereby said transverse bars lie in the same plane as the bottom edges of said plates.

PHILIP KERRIGAN, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,706,892 Lachman et al Mar. 26, 1929 1,750,039 Feltes Mar. 11, 1930 1,993,602 Green Mar. 5, 1935 2,208,020 Delanty July 16, 1940 2,335,181 Heath Nov. 23, 1943 2,338,444 Lachman Jan. 4, 1944 

